Ikeda Ken-ichi, Nakamura Hitoshi, Arakawa Masao, Matsumoto Naoyuki
National Institute for Agro-Environmental Sciences, 3-1-3 Kan-non dai, Tsukuba 305-8604, Japan.
Mycol Res. 2004 Jun;108(Pt 6):626-34. doi: 10.1017/s0953756204000061.
The diversity and vertical transmission of double-stranded (ds) RNA in Helicobasidium mompa and Rosellinia necatrix was examined by electrophoresis and Northern hybridization. These two fungi share the similar niche as root rot pathogens of trees in forests and orchards, and had diverse dsRNAs. The detection frequency of dsRNA in both fungi was different; in H. mompa, 68.4% (132 out of 193 MCGs; mycelial compatibility groups) had dsRNA, whereas 20.9% (53 out of 254 MCGs) in R. necatrix. dsRNA banding patterns and Northern blot analyses revealed the presence of various dsRNA elements in both fungi. Hyphal tip isolation was mostly unsuccessful to remove dsRNA with some exceptions. Sexual reproduction functioned to remove dsRNA in both fungi since dsRNA was not detected from single sexual spore cultures. Possible explanations for the difference in the detection frequency of dsRNA are discussed in terms of the differences in their sexual reproduction and other factors.
通过电泳和Northern杂交检测了桑卷担菌（Helicobasidium mompa）和紫纹羽病菌（Rosellinia necatrix）中双链（ds）RNA的多样性和垂直传播。这两种真菌作为森林和果园中树木根腐病的病原菌，具有相似的生态位，且拥有多样的dsRNA。两种真菌中dsRNA的检测频率不同；在桑卷担菌中，68.4%（193个菌丝体亲和群（MCG）中的132个）含有dsRNA，而在紫纹羽病菌中为20.9%（254个MCG中的53个）。dsRNA条带模式和Northern印迹分析表明，两种真菌中均存在各种dsRNA元件。除了一些例外情况，菌丝尖端分离大多无法去除dsRNA。由于在单性孢子培养物中未检测到dsRNA，有性生殖在两种真菌中都起到了去除dsRNA的作用。从它们有性生殖的差异和其他因素方面讨论了dsRNA检测频率差异的可能原因。
